Being turned on is distracting stuff. While your sex drive encourages you to get busy with a range of people, having a crush diverts your energy to win that person over. You can feel possessive and obsessive, and you can't stop fantasizing about them long enough to reel your eyeballs back in.

Feeling hot and bothered (and maybe twiddling your beard)? Being turned on is involuntary and diverts bloodflow to your private bits. There’s also a rush of blood to your head, which is why you feel so flushed around that pile of cutiepants.

Lust is like natural caffeine: Adrenaline pumps you up, which might explain why you can’t get to sleep when you’re fantasizing about sex. It’s also probably how Boyz II Men could make love to you all night long. (Wouldn't that get tiresome? Asking for a friend.)

You and your boo in the coupe are lip locking, but it's not just to get busy: Kissing can also help suss out potential mates, even if it's just for the night. When your saliva mingles, it's transmitting all sorts of sensory chemical information like smell and taste that let you know whether you'll want to make out with that person again.